/lib/lessphp/SourceMap/Generator.php

<?php



/**

 * Source map generator

 *

 * @package Less

 * @subpackage Output

 */

class Less_SourceMap_Generator extends Less_Configurable {



	/**

	 * What version of source map does the generator generate?

	 */

	const VERSION = 3;



	/**

	 * Array of default options

	 *

	 * @var array

	 */

	protected $defaultOptions = array(

			// an optional source root, useful for relocating source files

			// on a server or removing repeated values in the 'sources' entry.

			// This value is prepended to the individual entries in the 'source' field.

			'sourceRoot'			=> '',



			// an optional name of the generated code that this source map is associated with.

			'sourceMapFilename'		=> null,



			// url of the map

			'sourceMapURL'			=> null,



			// absolute path to a file to write the map to

			'sourceMapWriteTo'		=> null,



			// output source contents?

			'outputSourceFiles'		=> false,



			// base path for filename normalization

			'sourceMapBasepath'		=> ''

	);



	/**

	 * The base64 VLQ encoder

	 *

	 * @var Less_SourceMap_Base64VLQ

	 */

	protected $encoder;



	/**

	 * Array of mappings

	 *

	 * @var array

	 */

	protected $mappings = array();



	/**

	 * The root node

	 *

	 * @var Less_Tree_Ruleset

	 */

	protected $root;



	/**

	 * Array of contents map

	 *

	 * @var array

	 */

	protected $contentsMap = array();



	/**

	 * File to content map

	 *

	 * @var array

	 */

	protected $sources = array();



	/**

	 * Constructor

	 *

	 * @param Less_Tree_Ruleset $root The root node

	 * @param array $options Array of options

	 */

	public function __construct(Less_Tree_Ruleset $root, $contentsMap, $options = array()){

		$this->root = $root;

		$this->contentsMap = $contentsMap;

		$this->encoder = new Less_SourceMap_Base64VLQ();



		$this->SetOptions($options);





		// fix windows paths

		if( isset($this->options['sourceMapBasepath']) ){

			$this->options['sourceMapBasepath'] = str_replace('\\', '/', $this->options['sourceMapBasepath']);

		}

	}



	/**

	 * Generates the CSS

	 *

	 * @return string

	 */

	public function generateCSS(){

		$output = new Less_Output_Mapped($this->contentsMap, $this);



		// catch the output

		$this->root->genCSS($output);





		$sourceMapUrl				= $this->getOption('sourceMapURL');

		$sourceMapFilename			= $this->getOption('sourceMapFilename');

		$sourceMapContent			= $this->generateJson();

		$sourceMapWriteTo			= $this->getOption('sourceMapWriteTo');



		if( !$sourceMapUrl && $sourceMapFilename ){

			$sourceMapUrl = $this->normalizeFilename($sourceMapFilename);

		}



		// write map to a file

		if( $sourceMapWriteTo ){

			$this->saveMap($sourceMapWriteTo, $sourceMapContent);

		}



		// inline the map

		if( !$sourceMapUrl ){

			$sourceMapUrl = sprintf('data:application/json,%s', Less_Functions::encodeURIComponent($sourceMapContent));

		}



		if( $sourceMapUrl ){

			$output->add( sprintf('/*# sourceMappingURL=%s */', $sourceMapUrl) );

		}



		return $output->toString();

	}



	/**

	 * Saves the source map to a file

	 *

	 * @param string $file The absolute path to a file

	 * @param string $content The content to write

	 * @throws Exception If the file could not be saved

	 */

	protected function saveMap($file, $content){

		$dir = dirname($file);

		// directory does not exist

		if( !is_dir($dir) ){

			// FIXME: create the dir automatically?

			throw new Exception(sprintf('The directory "%s" does not exist. Cannot save the source map.', $dir));

		}

		// FIXME: proper saving, with dir write check!

		if(file_put_contents($file, $content) === false){

			throw new Exception(sprintf('Cannot save the source map to "%s"', $file));

		}

		return true;

	}



	/**

	 * Normalizes the filename

	 *

	 * @param string $filename

	 * @return string

	 */

	protected function normalizeFilename($filename){

		$filename = str_replace('\\', '/', $filename);

		$basePath = $this->getOption('sourceMapBasepath');



		if( $basePath && ($pos = strpos($filename, $basePath)) !== false ){

			$filename = substr($filename, $pos + strlen($basePath));

			if(strpos($filename, '\\') === 0 || strpos($filename, '/') === 0){

				$filename = substr($filename, 1);

			}

		}

		return sprintf('%s%s', $this->getOption('sourceMapRootpath'), $filename);

	}



	/**

	 * Adds a mapping

	 *

	 * @param integer $generatedLine The line number in generated file

	 * @param integer $generatedColumn The column number in generated file

	 * @param integer $originalLine The line number in original file

	 * @param integer $originalColumn The column number in original file

	 * @param string $sourceFile The original source file

	 */

	public function addMapping($generatedLine, $generatedColumn, $originalLine, $originalColumn, $sourceFile){

		$this->mappings[] = array(

			'generated_line' => $generatedLine,

			'generated_column' => $generatedColumn,

			'original_line' => $originalLine,

			'original_column' => $originalColumn,

			'source_file' => $sourceFile

		);





		$norm_file = $this->normalizeFilename($sourceFile);



		$this->sources[$norm_file] = $sourceFile;

	}





	/**

	 * Generates the JSON source map

	 *

	 * @return string

	 * @see https://docs.google.com/document/d/1U1RGAehQwRypUTovF1KRlpiOFze0b-_2gc6fAH0KY0k/edit#

	 */

	protected function generateJson(){



		$sourceMap = array();

		$mappings = $this->generateMappings();



		// File version (always the first entry in the object) and must be a positive integer.

		$sourceMap['version'] = self::VERSION;





		// An optional name of the generated code that this source map is associated with.

		$file = $this->getOption('sourceMapFilename');

		if( $file ){

			$sourceMap['file'] = $file;

		}





		// An optional source root, useful for relocating source files on a server or removing repeated values in the 'sources' entry.	This value is prepended to the individual entries in the 'source' field.

		$root = $this->getOption('sourceRoot');

		if( $root ){

			$sourceMap['sourceRoot'] = $root;

		}





		// A list of original sources used by the 'mappings' entry.

		$sourceMap['sources'] = array_keys($this->sources);







		// A list of symbol names used by the 'mappings' entry.

		$sourceMap['names'] = array();



		// A string with the encoded mapping data.

		$sourceMap['mappings'] = $mappings;



		if( $this->getOption('outputSourceFiles') ){

			// An optional list of source content, useful when the 'source' can't be hosted.

			// The contents are listed in the same order as the sources above.

			// 'null' may be used if some original sources should be retrieved by name.

			$sourceMap['sourcesContent'] = $this->getSourcesContent();

		}



		// less.js compat fixes

		if( count($sourceMap['sources']) && empty($sourceMap['sourceRoot']) ){

			unset($sourceMap['sourceRoot']);

		}



		return json_encode($sourceMap);

	}



	/**

	 * Returns the sources contents

	 *

	 * @return array|null

	 */

	protected function getSourcesContent(){

		if(empty($this->sources)){

			return;

		}

		$content = array();

		foreach($this->sources as $sourceFile){

			$content[] = file_get_contents($sourceFile);

		}

		return $content;

	}



	/**

	 * Generates the mappings string

	 *

	 * @return string

	 */

	public function generateMappings(){



		if( !count($this->mappings) ){

			return '';

		}



		// group mappings by generated line number.

		$groupedMap = $groupedMapEncoded = array();

		foreach($this->mappings as $m){

			$groupedMap[$m['generated_line']][] = $m;

		}

		ksort($groupedMap);



		$lastGeneratedLine = $lastOriginalIndex = $lastOriginalLine = $lastOriginalColumn = 0;



		foreach($groupedMap as $lineNumber => $line_map){

			while(++$lastGeneratedLine < $lineNumber){

				$groupedMapEncoded[] = ';';

			}



			$lineMapEncoded = array();

			$lastGeneratedColumn = 0;



			foreach($line_map as $m){

				$mapEncoded = $this->encoder->encode($m['generated_column'] - $lastGeneratedColumn);

				$lastGeneratedColumn = $m['generated_column'];



				// find the index

				if( $m['source_file'] ){

					$index = $this->findFileIndex($this->normalizeFilename($m['source_file']));

					if( $index !== false ){

						$mapEncoded .= $this->encoder->encode($index - $lastOriginalIndex);

						$lastOriginalIndex = $index;



						// lines are stored 0-based in SourceMap spec version 3

						$mapEncoded .= $this->encoder->encode($m['original_line'] - 1 - $lastOriginalLine);

						$lastOriginalLine = $m['original_line'] - 1;



						$mapEncoded .= $this->encoder->encode($m['original_column'] - $lastOriginalColumn);

						$lastOriginalColumn = $m['original_column'];

					}

				}



				$lineMapEncoded[] = $mapEncoded;

			}



			$groupedMapEncoded[] = implode(',', $lineMapEncoded) . ';';

		}



		return rtrim(implode($groupedMapEncoded), ';');

	}



	/**

	 * Finds the index for the filename

	 *

	 * @param string $filename

	 * @return integer|false

	 */

	protected function findFileIndex($filename){

		return array_search($filename, array_keys($this->sources));

	}



}